Electron trapping in metal-insulator-semiconductor structures on n - GaN with SiO 2 and Si 3 N 4 dielectrics

Electron trapping in Al -gate n - GaN ∕ nitrided-thin- Ga 2 O 3 ∕ SiO 2 and n - GaN ∕ Si 3 N 4 MIS capacitors was evaluated by capacitance-voltage ( C – V ) measurements. Significant positive flatband voltage shift ( Δ V fb ) was observed with increasing starting dc bias in the C – V measurements. For similar equivalent oxide thickness and under the same C – V measurement conditions, Δ V fb in the nitride was 3–10 times larger than in the oxide samples. It is suggested that flatband voltage shifts are due to border traps in SiO 2 and to interface and bulk traps in Si 3 N 4 samples.